Optical plate mounter

ABSTRACT

Optical plate mounter enabling the conventional flexible printing plate to be accurately aligned with the printing cylinder and mounted thereon by the use of adhesive tape having adhesive on each of its sides. Adjustable printing cylinder mounting fixtures are provided in advance of a horizontal plate mounting surface to align the peripheral surface of the printing cylinder with the plane of the plate mounting surface. A projector is disposed above the plate mounting surface and projects an optically correct grid on the plate mounting surface and printing plate and printing cylinder to insure accuracy in mounting the printing plate on the printing cylinder. The printing cylinder is indexed to enable a selected number of printing plates to be placed on the printing cylinder, and print in a predetermined sequence. A roll of adhesive tape commonly called sticky-back is mounted beneath and parallel to the printing cylinder. A parallel bar is mounted to be lowered directly onto the printing cylinder and serve as a guide for a cutting knife to accurately cut the sticky-back and attain a butt joint of the sticky-back when placed on the cylinder. A pressure roller is provided which can be lowered directly onto the printing cylinder to then press the printing plate to the stickyback.

Elite tates [72] Inventor David H. Mages 1246 Swainwood Drive, Glenview, Ill. 60025 [21] Appl. No 825,278

[22] Filed May 16, 1969 [45] Patented Oct. 26, 1971 [54] OPTICAL PLATE MOUNTER Primary Examiner-Benjamin A. Borchelt Assistant Examiner-G. E. Montone Attorney-Hill, Sherman, Meroni, Gross & Simpson ABSTRACT: Optical plate mounter enabling the conventional flexible printing plate to be accurately aligned with the printing cylinder and mounted thereon by the use of adhesive tape having adhesive on each of its sides. Adjustable printing cylinder mounting fixtures are provided in advance of a horizontal plate mounting surface to align the peripheral surface of the printing cylinder with the plane of the plate mounting surface. A projector is disposed above the plate mounting surface and projects an optically correct grid on the plate mounting surface and printing plate and printing cylinder to insure accuracy in mounting the printing plate on the printing cylinder. The printing cylinder is indexed to enable a selected number of printing plates to be placed on the printing cylinder, and print in a predetermined sequence. A roll of adhesive tape commonly called sticky-back is mounted beneath and parallel to the printing cylinder. A parallel bar is mounted to be lowered directly onto the printing cylinder and serve as a guide for a cutting knife to accurately cut the sticky-back and attain a butt joint of the sticky-back when placed on the cylinder. A pressure roller is provided which can be lowered directly onto the printing cylinder to then press the printing plate to the sticky-back.

PATENTEDom 26 Ian SHEET 10F 4 I N VIZN TOR.

A I 'l ()RNEYS zy/fages OPTICAL PLATE MOUNTER SUMMARY AND OBJECTS OF THE INVENTION System and apparatus for alignment of a flexible printing plate on a printing cylinder by projecting an optically correct alignment pattern directly on the printing plate and printing cylinder, together with an indexing selector which may be indexed to enable a selected number of printing plates to be placed on the same cylinder to print in a preselected sequence.

A principal object of the present invention, therefore, is to provide a novel and improved method and apparatus for accurately aligning a printing plate with a printing cylinder to be adhesively placed on the cylinder by projecting a preselected aligiing pattern on the printing plate and cylinder.

Another object of the invention is to provide an optical mounting system assuring accurate mounting of a printing plate on its printing cylinder.

Still another object of the invention is to provide an improved form of mounter for a rubber printing plate, utilizing a projector projecting an optically correct aligning pattern directly on the printing plate and cylinder, which is mechanically in line with and square with the printing cylinder,

A further object of the invention is to provide a simple and improved form of printing plate mounter in which the printing plate is aligned with the printing cylinder by optically projecting a grid on the printing plate and cylinder, and in which the cylinder is indexed to accommodate one or more plates to be mounted on the cylinder, with the images of plates aligned to print a succession of images, in a simple and expeditious manner.

Still another object of the invention is to improve upon the plate mounting devices heretofore in use for mounting flexible printing plates on printing cylinders, so arranged as to utilize an adhesive tape for mounting the plate to the cylinder and an optical projecting means for projecting an alignment pattern onto the plate mounting surface and printing cylinder, together with a parallel bar arrangement dropping directly onto the adhesive tape and enabling the tape to be cut to provide an accurate butt joint between the ends of the tape on the printing cylinder and allowing the plate to be placed at any point on the printing cylinder.

A still further object of the invention is to provide a novel form of plate mounting means for rubber printing plates in which a sticky-back tape is adhered to the cylinder and retains the plate to the cylinder, and in which a pressure roll is movable onto the place to adhere the plate to the sticky-back tape, without the necessity of touching the plate by the operator, and thereby eliminating variations in stretch in the plate.

Other objects, features and advantages of the invention will be readily apparent from the following description of a preferred embodiment thereof, taken in conjunction with the accompanying drawings, although variations and modifications may be effected without departing from the spirit and scope of the novel concepts of the disclosure.

DESCRIPTION OF THE DRAWING FIG. I is a fragmentary perspective view of a plate mounter constructed in accordance with the principles of the present invention.

FIG. 2 is a fragmentary perspective view, showing the projection of a grid pattern on the printing plate and printing cylinder.

FIG. 3 is a diagrammatic perspective view of the projector showing the grid slide in the projector.

FIG. 4 is a fragmentary front end view of the plate mounter shown in FIG. I, with certain parts broken away and certain other parts shown in transverse section.

FIG. 5 is a partial fragmentary side elevational view of the plate mounter, with certain parts broken away and certain other parts shown in longitudinal section; and

FIG. 6 is a transverse sectional view taken substantially along line VI-Vl of FIG. 4.

DESCRIPTION OF PREFERRED EMBODIMENT OF INVENTION In the embodiment of the invention illustrated in the drawings, I have shown an optical plate mounter 10 including a base frame 11 having parallel spaced sidewalls I2 and a flat top surface 13 connected between said sidewalls at the upper ends thereof, and shown in FIG. 1 as being formed integrally therewith. The sidewalls 12 are anchored in position on a work surface, such as a table 14, by the securing of bracket feet 15 extending laterally of said sidewalls 12 to the top of the table. In mounting the plate mounter 10 on the work surface 14 it should be so mounted that its front edge extends over the front of the work surface. The distance may be 2 inches, but may vary in accordance with the work surface used, the diameter of the printing cylinder and convenience in operating the plate mounter.

The plate mounter also has a tape supply bracket I7 suitably secured thereto, preferably after the plate mounter has been placed on its work surface 14. The tape supply bracket is centered in relation to the center of the top surface 13, and a plate mounting surface 19, thereof. so as to depend beneath the top of said table I4. The back of the tape supply bracket may abut the front of the table 14. Said tape supply bracket has two parallel spaced bracket anns 20, extending forwardly of the table 14 beneath the top of said table and forming a mounting for a roll of adhesive tape 21, commonly termed sticky-back. A removable pin 22 is provided to mount the sticky-back tape 21 between the bracket arms 20.

The sticky-back tape is unrolled about the axis of the pin 22, which is parallel to the axis of a printing cylinder 23. and may be of any conventional form having a sticky front surface and an adhesive or sticky back surface covered by a liner (not shown), which is torn off when adhering a printing plate to the printing cylinder 23. The stickyback tape may be of a width substantially equal to the width of the printing plate. so as to be adhesively secured to the printing cylinder on one side and uniformly adhere the printing plate to the printing cylinder on its opposite or back side as will hereinaher more clearly appear as this specification proceeds.

A projector 25 is spaced above the plate mounting surface 19 in alignment therewith and is mounted on a support leg 26 secured to the rear end of the frame 11 intermediate the sidewalls 12,12, and extending upwardly therefrom. The projector 25 may project an alignment pattern on a printing plate on the plate mounting surface 19 and on the printing cylinder 23, to enable the printing plate to be accurately aligned with the printing cylinder. The alignment pattern is shown in FIG. 2 as being a grid pattern indicated generally by reference character 27, but may be of various other desired forms.

A bifurcated fixture 29 is provided to detachably mount the printing cylinder 23 in advance of the plate mounting surface 19, to adjustably move said cylinder upwardly to align the periphery of said printing cylinder with said mounting surface, and to lower the printing cylinder when desired, to remove said printing cylinder form the fixture 29 and to replace it with another printing cylinder. The fixture 29 may be in the form of a casting, and includes a pair of parallel spaced arms 30 and 31 extending through an open portion of a front wall 32 of the frame 11 along opposite sides of the tape mounting bracket 17. The arms 30 and 31 are suitably connected by a crossframe structure 33 (FIGS. 4 and 5) and have right-angled upwardly extending bosses 35 at their rear ends, pivotally mounted on a transverse shaft 36. The shaft 36 is suitably mounted at its ends in brackets 37, depending from the bottom of the top surface 13 0f the frame ll.

Downward movement of the printing cylinder support fixture 29 is limited by a cam 39 on a transverse shaft 40. journaled in the plate mounter frame 11 in a suitable manner and extending outwardly of one sidewall I2 of said frame. As shown in FIG. 4, the cam 39 is in the form of an eccentric disk engaging the underside of the cross-frame structure 33 intermediate the ends thereof, and is movable by turning movement of the shaft 40, to raise the arms 30 and 31 of the fixture 29 from the solid line position shown in H6. 5, to the elevated position shown by broken lines in this figure.

The shaft 40 is shown in FIG. 4 as journaled in said frame at its left-hand end, when looking toward the front of the aparatus, in a bearing 41. Said bearing 41 is mounted in a a bearing boss 42 formed integrally with and extending inwardly of a left-hand sidewall 13 of said frame. The bearing 41 and shaft 40 extend through and outwardly of said sidewall 12 within a clamping cap 43. A collar 45 is secured to the shaft 40 inwardly of the left-hand sidewall 12 and forms an inner abutment for the bearing 41. A lever 46 is provided to turn the shaft 80 and cam 39 thereon to raise or lower the printing cylinder fixture 29. The lever 46 is shown as being in the form of an upright pin extending through a drilled hole in the clamping cap 43, and as having a downwardly facing shoulder 47 engaging the surface of the shaft 40. The lever 46 has a reduced diameter threaded portion 48 extending downwardly of the shoulder 47, and loosely extending through a drilled hole 49 extending diametrically through the shaft 40. The threaded end portion 48 of the lever 46 has threaded engagement with the clamping cap 43. A knob 50 is secured to the upper end of the lever 46 to afford a hand grip, to accommodate the hand to turn said lever and shaft 40 and raise or lower the printing cylinder fixture 29 and the printing cylinder 23 supported thereon.

The bearing 41 is secured to the bearing boss 42 and held from turning movement relative to said bearing boss in suitable manner. Play is provided between the end of the shaft 40 and the clamping cap 43. Limited play is also provided between the clamping cap 43 and the outer surface of the bearing 41. Thus, when it is desired to hold the cam 39 and printing cylinder 23 in a selected position of adjustment, it is merely necessary to turn the knob 50 and bring the clamping cap 43 into clamping engagement with the bearing 41.

The printing cylinder 23 may be a conventional printing cylinder, which may be made from aluminum or any other suitable material. A gear 51 is at the right-hand end of said cylinder. Said gear is conventional and serves to drive the cylinder when in the press. A hearing 53 extends along the interior of the printing cylinder and terminates at its right-hand end flush with an outer end face 54 of the gear 51. A shaft 55 is provided to detachably mount the printing cylinder 23 in the printing cylinder fixture 29, between the arms 30 and 31 thereof. 7

As shown in FIG. 4, the shaft 55 has a knobbed or knurled left-hand end portion 56 on the outside of the arm 30 of the fixture 29 and slidably extends through said fixture. The shaft 55 also has a shoulder 57 engaging the left-hand end of the bearing 53 for the printing cylinder 23. The shaft 55 extends through the bearing 53 into a drive member 59 journaled in the right-hand arm 31 on antifriction end thrust bearings 60,60. Said bearings extend about opposite sides of a disk 61, keyed or otherwise secured to said drive member. The bearings 60,60 provide a rotatable mounting for the drive member 59 in the arm 31 and also retain said drive member from movement along its axis in either direction.

A friction disk 62 is suitably mounted on the inner end of the drive member 59 and forms an abutment and friction drive member for the face 54 of the printing cylinder gear 51 and the printing cylinder 23. The shaft 55 has a threaded reduced diameter right-hand end portion 66 extending within a stepped bore 67 leading axially into the drive member 59, from the inner end thereof, and may be threaded in the reduced diameter end portion of said stepped bore.

Thus, when the printing cylinder 23 is mounted on the shaft 55 and the end 66 of said shaft is threaded in the stepped bore 67, the shoulder 57 on said shaft will bring the face 54 of the gear 51 into engagement with the friction disk 62, to accommodate turning of the printing cylinder 23 by hand into certain preselected indexed positions upon turning movement of a selector knob 69, secured to the right-hand end portion of the drive member 59 on the outside of the bracket arm 31.

The selector knob 69 has an outer enlarged diameter knurled portion and a reduced diameter indexing barrel 71 extending inwardly therefrom and terminating at its inner end into an annular member 72 generally forming an end closure for the outer end of the support arm 31 to close the outer end portion of said am and retain the outer bearing 60 within said arm.

The reduced diameter cylindrical portion 71 of the selector knob 69 has a series of circumferentially spaced scribe lines extending axially therealong and terminating at the annular member 72 and designated by indicia such as 0" of the selector knob, 3" to indexing the printing cylinder where images are to be stepped three around the cylinder and 4" where images are to be stepped four around the indexing cylinder. The scribe line designated "0" cooperates with an indexing line or arrow 75 on the top peripheral surface of the annular member 72 and extending axially along said surface. The indexing line or arrow 75 cooperates with a scribe line 77 extending axially along the surface of the printing cylinder 23, and adapted to be aligned with the 0" indexing line on the selector handle or knob 69 when applying sticky-back to the cylinder and aligning the printing plate with the cylinder.

The drive member 59 and indexing knob 69 are held in selected positions about the axis of the shafl 55, by an indexing locking pin 79 on the inner end of a pin 80 and extending diametrically of the printing cylinder shaft 55 (FIG. 6). The pin 80 is slidably guided in a shouldered fitting 81 fitting within a boss 82 extending radially of the arm 31 and shown as being formed integrally therewith. The pin 79 is adapted to engage with one of a series of notches 83 formed in the periphery of the disk 61 to hold said disk, the drive member 59 and the selector knob 69 in an indexed position and to thereby hold the printing cylinder 23 in an indexed position.

The notches 83 are diagrammatically shown herein, and may be arranged in accordance with the printing plates and successive images thereon and correspond to the axially extending lines and indicia on the reduced diameter portion 71 of the selector knob 69.

The flange of the flanged fitting 81 abuts the outer side of the boss 82. The inner end of the flanged fitting 81 has an inwardly opening spring chamber 85 opening to the disk 61 and forming a chamber for a compression spring 86, seated in the inner end wall of said chamber. The inner end of the compression spring 86 seats against a pin 87 extending transversely through the pin 80.

An indexing knob 88 is mounted on the outer end of the pin 80 and affords a means for withdrawing the indexing pin 79 from a selected notch 83 to accommodate turning movement of the selector knob 69 and drive member 59. A stop pin 89 is mounted in the fitting 81 and extends outwardly therefrom in an axial direction into a socket 90 in the inner surface of the indexing knob 88. The pin 89 serves to hold the indexing pin 79 out of engagement with a selected notch as withdrawn therefrom against the bias of the spring 86. This is attained by pulling on the indexing knob to release the pin 89 from the socket 90 and then turning the knob to engage the end of the pin 89.

A straight edge 91 is mounted on the outer end of a crossbar 92 and serves as a knife guide for trimming and cutting the sticky-back. The crossbar 92 extends across and is formed integrally with a pair of arms 93 extending downwardly through slots 94 in the top surface 13 of the frame 11. Said arms have right-angled inner end portions extending in a forward direction and pivoted to bosses 95 depending from the underside of the top surface 13 of the frame 11, on pivot pins 96 (FIG. 5). The arms 93 are so arranged and pivoted to the undersurface of the top surface 13, to accommodate movement of the straight edge 91 downwardly along the plate mounting surface 19 beyond the forward end thereof into engagement with the printing cylinder to form a guide and straight edge. parallel to the scribe line 77 extending along the printing cylinder, to accommodate cutting of the tape or sticky-back with a razor or the like, with its end parallel to and in alignment with the scribe line 77.

ln wrapping sticky-back on the printing cylinder, assuming the printing cylinder has been mounted in its printing fixture on the shaft 55 and the fixture has been raised until the top surface of the cylinder 23 is level with the plate mounting surface 19, the straight edge or cutting knife guide 91 may be lowered onto the printing cylinder, and the printing cylinder may be turned on the shaft 55 until the scribe line 77 is lined up with said cutting knife guide. The selector knob 69 should then be locked in its 0 position and the scribe line 77 should register with this position. The printing cylinder may then be locked against the friction disk 62 by turning of the knob 56 and shaft 55.

The cutting knife guide may then be raised off the printing cylinder and the cut end of the sticky-back tape may be brought onto the printing cylinder 23 with its end overlapping the scribe line on the printing cylinder. The cutting knife guide 91 may then be lowered onto the sticky-back on the cylinder, and the sticky-back may be out along the scribe line 77 by a sharp knife or razor blade.

The lock knob 88 may then be pulled outwardly to release the indexing pin 79 from a notch 83. The selector knob 69 may then be rotated in a clockwise direction turning the printing cylinder 23 therewith to wrap said cylinder until the stickyback overlaps the scribe line on the cylinder. The selector knob 69 may again be locked in the 0" position, to hold the scribe line 77 in alignment with the "0" position.

The cutting knife guide or straight edge 91 may then be lowered into engagement with the sticky-back wrapped, about the cylinder, and the sticky-back may be out along the scribe line, to provide an even butt joint of the sticky-back wrapping the printing cylinder 23 and adhered thereto.

A pressure roller 99, which may be a rubber roll or rubber covered roll, is provided on the upper end of a roller frame 100, pivoted beneath the top surface 13 of the frame 11 and including spaced arms 101 extending through slots 102, spaced rearwardly and outwardly of the slots 94. The spaced arms 101, like the spaced arms 93, have right-angled inner end portions extending forwardly of the slots 102 and pivotally mounted at their forward ends on bosses 103, depending from the bottom of the top surface 13 on pivot pins 104. The pressure roller 99 is provided to contact the surface of the rubber plate on the printing cylinder by the weight of the roller itself. In some cases, however, it may be necessary to increase or decrease the pressure by grasping a crossarm 105 extending between the arms 101 and exerting a pushing or pulling force on said arms.

The grid projector 25 includes a boxlike housing 106 containing a projection unit 107, two illuminating lamps 109 serving to illuminate the plate mounter prior to the projection ofa grid pattern thereon.

The projection unit 107 may be ofa conventional form and is no part of the present invention so need not herein be shown or described in detail. Said projection unit includes the usual projecting lens (not shown), cooling fan (not shown) and a projection bulb (not shown), which may be controlled by a foot switch (not shown). A metal grid slide 111 is mounted in the bottom of the projection unit and may be slidably adjusted back and forth. The metal grid slide 111 contains a glass slide 112, which is adjustable in the metal grid slide from side to side and has a small amount of adjustment back and forth in the grid slide or clip.

The mounting of the metal grid slide and glass grid slide and the means for adjusting said slides are no part of the present invention, except insofar as they form a means for projecting a grid on the plate mounting surface 19 and on the printing cylinder. A detailed description thereof, therefore, is not necessary to fully understand the present invention, since the mounting means and adjustment means may be of various well-known forms.

The glass grid slide is placed in the metal slide and projection unit with three separated grid lines toward the back of the projection unit. This will reverse the image so the three separated grid lines will be projected on the printing cylinder. The scribe line 77 extending along the printing cylinder may then be aligned with the center grid line, upon turning the printing cylinder and positioning the selector knob 69 in its 0 position.

When projecting an alignment image such as a grid on the mounting surface 19, when the glass grid slide is in proper alignment relative to the printing cylinder, the focus may be sharpened where required by a conventional focusing lens (not shown) as the grid projector unit is turned on and the lamps 109 are turned off. The turning on of the projector and the turning off of the lamps 109 may be controlled by a foot switch (not shown). The lamps 109 may be controlled by a toggle switch when the projector is turned off.

Assuming the front cover or door 116 for the projector housing 106 is closed, and the printing plate is placed on the printing surface 19, with the head or leading end of the plate facing the printing cylinder 23, the projector may then be turned on and the printing plate may be aligned with the linear and transverse grid lines, which are also aligned with the projected grid lines on the printing cylinder. When aligning the plate with the grid lines projected thereon, a piece of the sticky-back liner material may be placed between the cylinder and printing plate until ready to press the plate against the sticky-back. The leading edge of the plate being parallel to and in alignment with the scribe line 77 and the sticky-back liner material between the cylinder and printing plate being removed, the rubber pressure roll 99 may then be lowered to contact the surface of the rubber printing plate on the printing cylinder.

The indexing locking knob 88 may then be grasped and pulled outwardly and locked in its release position. The selector knob 69 may then be turned in a counterclockwise direction to feed the printing plate onto the cylinder. The rubber pressure roll 99 will exert a uniform pressure on the printing plate and printing cylinder which may be manually increased or decreased, as previously described. During the feeding operation of the printing plate to the cylinder, the linear alignment of the printing plate with the printing surface may be observed, by watching the plate feed along the projected grid lines running from front to back.

The images on the plate, where the plate is arranged to successively print the same images, spaced circumferentially and laterally with respect to each other, may be checked by turning the selector knob 69 to each indexed position so the projected grid line running from right to left across the cylinder will line up at the same point on each image of the plate around the cylinder.

As for example, if the plate has four images spaced circumferentially and laterally relative to each other, the selector knob should first be at its 0 position and then may be turned to each of three positions marked 4."

Where the circumferential distance between images is too great, and it is not possible to mount the plates correctly stepped and repeated around and across the cylinder, the plates may then be cut and mounted individually along the cylinder.

As for example, where individual plates are mounted around and across the cylinder, the selector knob 69 is first locked in the 0" position, and the grid lines are then projected onto the plate and cylinder.

A first row of plates may then be aligned across the cylinder on one of the projected grid lines running from left to right on the cylinder.

When the first row of plates has been mounted across the cylinder, the selector knob 69 is turned to the next index position and the next row of plates may then be mounted across the cylinder, using the same projected grid line. As for example, if the plate is to be stepped three around the cylinder, the 0" indexing position should first be used and the two positions marked 3 should then be used.

Thus, once the first row of plates has been mounted across the cylinder, the succeeding plates in the same rows around the cylinder can be accurately mounted by placing the same definite reference point on each plate on the same grid line following around the cylinder.

lt may be seen from the foregoing that a simple form of plate mounter has been provided in which accuracy in mounting the plates around the printing cylinder is assured by projecting an alignment or grid pattern on the mounting surface and cylinder and accurately aligning the cylinder with the grid pattern for each image on the plate.

It may further be seen that by the system and apparatus of the present invention, an adhesive tape having adhesive on its front and back sides may be adhesively mounted on the cylinder with an accurate butt joint, by the utilization of the straight edge or cutting knife guide 91 movable into engagement with the top surface of the adhesive tape and registering with the scribe line 77, as the tape is placed on the cylinder, and guiding a knife to cut the leading end of the tape is applied to the cylinder and trim the tape to length as wrapped on the cylinder.

It may further be seen that the plate when aligned with the cylinder may be adhesively secured thereto by use of the rubber pressure roll 99, uniformly wrapping the printing plate around the cylinder, with the images in the correct repeat positions under the control of the selector knob 69, and that one or more printing plates may be placed along the cylinder and aligned with the projected grid pattern, with the images thereof accurately located along the cylinder, by indexing the cylinder by the selector knob 69, to effect a printing operation, as the cylinder is removed from its fixture 29 and placed in the press.

I claim as my invention:

1. In an optical printing plate mounter for mounting a flexible printing plate on a printing cylinder, and in combination with a printing plate having a straight leading edge and a printing cylinder,

a frame having a top flat plate mounting surface,

a printing cylinder fixture supported on said frame beneath said flat plate mounting surface and extending in advance of said flat plate mounting surface,

means detachably mounting the printing cylinder on said fixture to position the top surface of said cylinder in the plane of said flat plate mounting surface to form a continuation thereof,

a projector mounted on said frame above and in alignment with said flat plate mounting surface,

an alignment pattern plate associated with said projector to effect projection of an alignment pattern downwardly on the top of said fiat plate mounting surface and said printing cylinder,

means turning the printing cylinder into a position corresponding with said alignment pattern, and

means separate from said mounting surface and mounted on said frame for movement toward and from said printing cylinder to exert pressure on the printing plate and cylinder and adhere the printing plate to said cylinder in registry with the pattern projected onto said printing plate and printing cylinder.

2. The optical plate mounter of claim 1, wherein the means turning the printing cylinder is effective to turn the printing cylinder into the step and repeat positions of the printing plate and comprises,

an indexing selector rotatable about the axis of the printing cylinder,

friction means engaging the indexing selector with the printing cylinder, and

locking means indexing the selector and printing cylinder in certain preselected indexed positions.

3. The optical plate mounter of claim 2, wherein the printing cylinder fixture is vertically movable relative to said flat plate mounting surface, and wherein means are provided for raising and lowering said fixture and holding the top of said cylinder to the plane of said flat plate mounting surface.

4. The optical plate mounter of claim 2,

including a bracket at the front of said frame and extending beneath said printing cylinder fixture and in advance thereof, and forming a mounting for a roll of adhesive tape, holding the rol of tape for unwinding about an axis parallel to the axis of the printing cylinder, to be applied to said cylinder and to adhesively secure the printing plate thereto,

a straight edge extending above said flat plate mounting surface rearwardly of the forward end thereof,

means mounting said straight edge for angular movement about an axis parallel to the axis of rotation of the printing cylinder into engagement with the surface of the printing cylinder and in registry with a 0" indexed position of the printing cylinder, to afford a guide for cutting the adhesive tape parallel to the axis of the printing cylinder, along the surface of the cylinder, on applying the tape to the printing cylinder and for cutting the tape to length as wrapped about the printing cylinder to provide a butt joint between adjacent ends of the adhesive tape.

5. A plate mounter in accordance with claim I,

wherein a scribe line extends across the printing cylinder axially along the periphery thereof, and

wherein the alignment pattern is a grid pattern including at least one cross line projected on the printing cylinder and forming an index line for said cylinder and accommodating registry of said scribe line with said cross line.

6. The plate mounter of claim 2,

wherein the printing cylinder fixture is vertically adjustable,

and

wherein means are provided to lower the printing cylinder to accommodate removal of the printing cylinder from the fixture and to raise the fixture and bring the top peripheral portion of the printing cylinder on a level with the horizontal surface of the plate mounting surface.

7. A plate mounter in accordance with claim 6,

wherein a tape supply bracket is mounted beneath the printing cylinder,

wherein a roll of adhesive tape is mounted on said bracket for unwinding about an axis parallel to the axis of the printing cylinder to accommodate adhering of the tape to the surface of the printing cylinder,

wherein a knife guide is mounted on said frame for movement toward and from the printing cylinder and extends transversely of the cylinder to accommodate cutting of the tape along said scribe line, and

wherein the tape has a sticky-back adhering the printing plate to the printing cylinder.

8. The plate mounter of claim 1, in which the means mounted on the frame for movement into position to exert pressure on the printing plate and cylinder comprises a pressure roll, and

wherein a roller frame forms a mounting for said pressure roll and has a pair of arms pivotally mounted on said frame for angular movement about coaxial axes disposed rearwardly of said flat plate mounting surface and at opposite sides thereof, said arms being of sufficient length to accommodate manual lowering movement of said roller into engagement with said printing cylinder and a printing plate being mounted thereon, to exert pressure on the printing plate as wrapped on the printing cylinder under manual control. 

2. The optical plate mounter of claim 1, wherein the means turning the printing cylinder is effective to turn the printing cylinder into the step and repeat positions of the printing plate and comprises, an indexing selector rotatable about the axis of the printing cylinder, friction means engaging the indexing selector with the printing cylinder, and locking means indexing the selector and printing cylinder in certain preselected indexed positions.
 3. The optical plate mounter of claim 2, wherein the printing cylinder fixture is vertically movable relative to said flat plate mounting surface, and wherein means are provided for raising and lowering said fixture and holding the top of said cylinder to the plane of said flat plate mounting surface.
 4. The optical plate mounter of claim 2, including a bracket at the front of said frame and extending beneath said printing cylinder fixture and in advance thereof, and forming a mounting for a roll of adhesive tape, holding the roll of tape for unwinding about an axis parallel to the axis of the printing cylinder, to be applied to said cylinder and to adhesively secure the printing plate thereto, a straight edge extending above said flat plate mounting surface rearwardly of the forward end thereof, means mounting said straight edge for angular movement about an axis parallel to the axis of rotation of the printing cylinder into engagement with the surface of the printing cylinder and in registry with a ''''0'''' indexed position of the printing cylinder, to afford a guide for cutting the adhesive tape parallel to the axis of the printing cylinder, along the surface of the cylinder, on applying the tape to the prinTing cylinder and for cutting the tape to length as wrapped about the printing cylinder to provide a butt joint between adjacent ends of the adhesive tape.
 5. A plate mounter in accordance with claim 1, wherein a scribe line extends across the printing cylinder axially along the periphery thereof, and wherein the alignment pattern is a grid pattern including at least one cross line projected on the printing cylinder and forming an index line for said cylinder and accommodating registry of said scribe line with said cross line.
 6. The plate mounter of claim 2, wherein the printing cylinder fixture is vertically adjustable, and wherein means are provided to lower the printing cylinder to accommodate removal of the printing cylinder from the fixture and to raise the fixture and bring the top peripheral portion of the printing cylinder on a level with the horizontal surface of the plate mounting surface.
 7. A plate mounter in accordance with claim 6, wherein a tape supply bracket is mounted beneath the printing cylinder, wherein a roll of adhesive tape is mounted on said bracket for unwinding about an axis parallel to the axis of the printing cylinder to accommodate adhering of the tape to the surface of the printing cylinder, wherein a knife guide is mounted on said frame for movement toward and from the printing cylinder and extends transversely of the cylinder to accommodate cutting of the tape along said scribe line, and wherein the tape has a sticky-back adhering the printing plate to the printing cylinder.
 8. The plate mounter of claim 1, in which the means mounted on the frame for movement into position to exert pressure on the printing plate and cylinder comprises a pressure roll, and wherein a roller frame forms a mounting for said pressure roll and has a pair of arms pivotally mounted on said frame for angular movement about coaxial axes disposed rearwardly of said flat plate mounting surface and at opposite sides thereof, said arms being of sufficient length to accommodate manual lowering movement of said roller into engagement with said printing cylinder and a printing plate being mounted thereon, to exert pressure on the printing plate as wrapped on the printing cylinder under manual control. 